Question

Which of the following are possible explicit formulas for the nth term of the constant velocity sequence below? Check all that apply. 10, 17, 24, 31, ...

Answer 1

We have an arithmetic progression:
Nth=an
an=a₁+(n-1)d
a₁ is the first term.
n=number of terms.
d=common difference

10,17,24,31...
a₁=10
d=a₂-a₁=17-10=7

Therefore:
Nth=an
an=a₁+(n-1)d
an=10+(n-1)7
an=10+7n-7
an=7n+3.

Therefore: the formula for the nth is, an=a+(n-1), in this case; an=7n+3,

To check:
a₁=7*1+3=10
a₂=7*2+3=17
a₃=7*3+3=24
a₄=7*4+3=31
a₅=7*5+3=38.......